The test was unnecessarily depending on InnoDB purge, which can
sometimes fail to proceed.
Let us rewrite the test to use BEGIN;INSERT;ROLLBACK to cause the
immediate removal of the desired records.
The problem was that xtradb has innodb_purge_threads default 1 (plain
innodb defaults to 0).
The test sets a special debug variable and relies on it to force
purge to happen. But when using background purge threads, this does
not work, the debug code is not made to handle this, so occasionally
the test times out waiting for the purge to occur.
Fix by explicitly setting innodb_purgee_threads=0 for this test.
btr_lift_page_up() writes wrong page number (different by -1) for upper than father page.
But in almost all of the cases, the father page should be root page, no upper
pages. It is very rare path.
In addition the leaf page should not be lifted unless the father page is root.
Because the branch pages should not become the leaf pages.
rb://1336 approved by Marko Makela.
